Thermal process chamber lid with backside pumping

ABSTRACT

Process chamber lid assemblies and process chambers comprising same are described. The lid assembly has a housing with a gas dispersion channel in fluid communication with a lid plate. A contoured bottom surface of the lid plate defines a gap to a top surface of a gas distribution plate. A pumping channel is formed between an upper outer peripheral contour of the gas distribution plate and the lid plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/467,669, filed Jun. 7, 2019, which claims priority to U.S.Provisional Application No. 62/853,699, filed May 28, 2019, all of whichis hereby incorporated by reference herein.

TECHNICAL FIELD

Embodiments of the present disclosure pertain to the field of electronicdevice manufacturing. In particular, embodiments of the disclosure aredirected to apparatus for delivering reactive gases in semiconductordevice manufacturing.

BACKGROUND

Reliably producing submicron and smaller features is one of the keytechnologies for the next generation of very large scale integration(VLSI) and ultra large scale integration (ULSI) of semiconductordevices. However, as the fringes of circuit technology are pressed, theshrinking dimensions of interconnects in VLSI and ULSI technology haveplaced additional demands on the processing capabilities. The multilevelinterconnects that lie at the heart of VLSI and ULSI technology useprecise processing of high aspect ratio features, such as vias and otherinterconnects. Reliable formation of these interconnects is veryimportant to VLSI and ULSI success and to the continued effort toincrease circuit density and quality of individual substrates.

As circuit densities increase, the widths of interconnects, such asvias, trenches, contacts, and other features, as well as the dielectricmaterials between, decrease while the thickness of the dielectric layersremain substantially constant, resulting in increased height-to-widthaspect ratios of the features. Many traditional deposition processeshave difficulty filling submicron structures and providing good stepcoverage for surface features.

Atomic layer deposition (ALD) is a deposition technique being exploredfor the deposition of material layers over features having high aspectratios. One example of an ALD process includes the sequentialintroduction of pulses of gases. For instance, one cycle for thesequential introduction of pulses of gases may contain a pulse of afirst reactant gas, followed by a pulse of a purge gas and/or a pumpevacuation, followed by a pulse of a second reactant gas, and followedby a pulse of a purge gas and/or a pump evacuation. The term “gas” asused herein is defined to include a single gas or a plurality of gases.Sequential introduction of separate pulses of the first reactant and thesecond reactant may result in the alternating self-limiting adsorptionof monolayers of the reactants on the surface of the substrate and,thus, forms a monolayer of material for each cycle. The cycle may berepeated to form a film with a predetermined thickness. A pulse of apurge gas and/or a pump evacuation between the pulses of the firstreactant gas and the pulses of the second reactant gas serves to reducethe likelihood of gas phase reactions of the reactants due to excessamounts of the reactants remaining in the chamber.

In some chamber designs for ALD processing, precursors and gases aredelivered using a funnel lid through which precursor is distributedthrough multiple injectors above a funnel shaped lid. The injectorsgenerate a circular motion of the injected gas which distributes throughthe funnel profile at the center of the lid. The rotational inertia ofthe gas/ALD precursor molecules distributes the molecules from center toedge resulting in improved uniformity deposition.

It has been observed that reactive gases become trapped between the lidplate and the showerhead during processing resulting in non-uniformityof the deposited films. Accordingly, there is an ongoing need in the artfor methods and apparatus to improve uniformity of deposited films.

SUMMARY

One or more embodiments of the disclosure are directed to processchamber lid assemblies. A housing encloses a gas dispersion channel thatextends along a central axis of the housing. The gas dispersion channelhas an upper portion and a lower portion. A lid plate is coupled to thehousing and has a contoured bottom surface that extends downwardly andoutwardly from a central opening coupled to the lower portion of the gasdispersion channel to a peripheral portion of the lid plate. A gasdistribution plate is disposed below the lid plate and has an upperouter peripheral contour configured to form a pumping channel betweenthe gas distribution plate and the lid plate. The gas distribution platehas a top surface and a bottom surface with a plurality of aperturesdisposed through the gas distribution plate from the top surface to thebottom surface. The contoured bottom surface of the lid plate and topsurface of the gas distribution plate define a gap.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments. The embodiments as described herein areillustrated by way of example and not limitation in the figures of theaccompanying drawings in which like references indicate similarelements.

FIG. 1 depicts a schematic view of a process chamber in accordance withsome embodiments of the present disclosure;

FIG. 2 depicts a schematic cross-sectional view of a process chamber inaccordance with some embodiments of the present disclosure;

FIG. 3 depicts a schematic cross-sectional view of a lid assembly inaccordance with some embodiments of the present disclosure;

FIGS. 4A-C depict schematic views of apertures disposed through a gasdistribution plate in accordance with embodiments of the presentdisclosure;

FIG. 5 shows a schematic cross-sectional view of a lid assembly inaccordance with one or more embodiments of the disclosure;

FIG. 6A shows a schematic cross-sectional view of a lid plate inaccordance with one or more embodiments of the disclosure;

FIG. 6B shows a schematic cross-sectional view of a lid assembly inaccordance with one or more embodiments of the disclosure;

FIG. 7 shows a schematic cross-sectional view of a lid assembly inaccordance with one or more embodiment of the disclosure; and

FIG. 8 shows a schematic cross-sectional view of a lid assembly inaccordance with one or more embodiment of the disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. The figures are not drawn to scale and may be simplifiedfor clarity. Elements and features of one embodiment may be beneficiallyincorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

Before describing several exemplary embodiments of the disclosure, it isto be understood that the disclosure is not limited to the details ofconstruction or process steps set forth in the following description.The disclosure is capable of other embodiments and of being practiced orbeing carried out in various ways.

A “substrate” as used herein, refers to any substrate or materialsurface formed on a substrate upon which film processing is performedduring a fabrication process. For example, a substrate surface on whichprocessing can be performed include materials such as silicon, siliconoxide, strained silicon, silicon on insulator (SOI), carbon dopedsilicon oxides, amorphous silicon, doped silicon, germanium, galliumarsenide, glass, sapphire, and any other materials such as metals, metalnitrides, metal alloys, and other conductive materials, depending on theapplication. Substrates include, without limitation, semiconductorwafers. Substrates may be exposed to a pretreatment process to polish,etch, reduce, oxidize, hydroxylate, anneal and/or bake the substratesurface. In addition to film processing directly on the surface of thesubstrate itself, in the present disclosure, any of the film processingsteps disclosed may also be performed on an under-layer formed on thesubstrate as disclosed in more detail below, and the term “substratesurface” is intended to include such under-layer as the contextindicates. Thus for example, where a film/layer or partial film/layerhas been deposited onto a substrate surface, the exposed surface of thenewly deposited film/layer becomes the substrate surface.

As used in this specification and the appended claims, the terms“precursor”, “reactant”, “reactive gas” and the like are usedinterchangeably to refer to any gaseous species that can react with thesubstrate surface.

Embodiments of the present disclosure provide apparatus and methods thatmay be used to clean substrate processing chambers, such as an atomiclayer deposition (ALD) chamber, and to deposit materials during, forexample, an ALD process. Embodiments include substrate processingchambers and gas delivery systems which may include a remote plasmasource and a gas distribution plate. The following process chamberdescription is provided for context and exemplary purposes, and shouldnot be interpreted or construed as limiting the scope of the disclosure.

FIG. 1 is a schematic view of a substrate processing chamber (processchamber 100) including a gas delivery system 130 adapted for ALDprocesses in accordance with some embodiments of the present disclosure.FIG. 2 is a cross-sectional view of the process chamber 100. Processchamber 100 includes a chamber body 102 having a processing volumewithin the chamber body 102 and beneath the chamber lid assembly 132.Slit valve 108 in the process chamber 100 provides access for a robot(not shown) to deliver and retrieve a substrate 110, such as a 200 mm or300 mm semiconductor wafer or a glass substrate, to and from the processchamber 100. A chamber liner 177 is disposed along the walls of theprocess chamber 100 to protect the chamber from corrosive gases usedduring processing/cleaning.

A substrate support 112 supports the substrate 110 on a substratereceiving surface 111 in the process chamber 100. The substrate support112 is mounted to a lift motor 114 for raising and lowering thesubstrate support 112 and the substrate 110 disposed on the substratesupport. A lift plate 116 (shown in FIG. 2), connected to a lift motor118, is mounted in the process chamber 100 to raise and lower lift pins120 movably disposed through the substrate support 112. The lift pins120 raise and lower the substrate 110 over the surface of the substratesupport 112. The substrate support 112 may include a vacuum chuck (notshown), an electrostatic chuck (not shown), or a clamp ring (not shown)for securing the substrate 110 to the substrate support 112 during adeposition process.

The temperature of the substrate support 112 may be adjusted to controlthe temperature of the substrate 110. For example, substrate support 112may be heated using an embedded heating element, such as a resistiveheater (not shown), or may be heated using radiant heat, such as heatinglamps (not shown) disposed above the substrate support 112. A purge ring122 may be disposed on the substrate support 112 to define a purgechannel 124 which provides a purge gas to a peripheral portion of thesubstrate 110 to prevent deposition on the peripheral portion of thesubstrate 110.

Gas delivery system 130 is disposed at an upper portion of the chamberbody 102 to provide a gas, such as a process gas and/or a purge gas, toprocess chamber 100. A vacuum system (not shown) is in communicationwith a pumping channel 179 to evacuate any desired gases from theprocess chamber 100 and to help maintain a desired pressure or pressurerange inside the process chamber 100.

In some embodiments, the chamber lid assembly 132 includes a gasdispersion channel 134 extending through a central portion of thechamber lid assembly 132. As shown in FIGS. 1 and 2, the gas dispersionchannel 134 extends perpendicularly toward the substrate receivingsurface 111 and also extends along a central axis 133 of the gasdispersion channel 134, through lid plate 170, and to bottom surface160. In some embodiments, an upper portion of the gas dispersion channel134 is substantially cylindrical along central axis 133 and a lowerportion of the gas dispersion channel 134 tapers away from central axis133. The bottom surface 160 is sized and shaped to substantially coverthe substrate 110 disposed on the substrate receiving surface 111 of thesubstrate support 112. The bottom surface 160 tapers from an outer edgeof the lid plate 170 towards the gas dispersion channel 134. The gasdelivery system 130 may provide one or more gasses to the gas dispersionchannel 134 to process the substrate 110. In some embodiments, the gasdelivery system 130 may be coupled to the gas dispersion channel 134 viaone gas inlet. In some embodiments, such as that shown in FIG. 3, thegas delivery system may be coupled to the gas dispersion channel 134 viaa plurality of inlets.

As illustrated in FIG. 3, circular gas flow 174, which illustrates theflow of process gases through the gas dispersion channel 134, maycontain various types of flow patterns. In some embodiments, processinggases may be forced to make revolutions around central axis 133 of gasdispersion channel 134 while passing through the dispersion channel. Insuch embodiments, the circular gas flow 174 may contain various types ofcircular flow patterns, such as a vortex pattern, a helix pattern, aspiral pattern, or derivatives thereof.

Although providing a circular gas flow 174 is beneficial for manyapplications, the inventors have discovered that in some applications,the circular gas flow can lead to non-uniform processing results. Theinventors have observed the gas flow may lead to a donut-shapeddeposition profile near a center of the substrate 110 being processed.The donut-shaped profile may be caused by the funnel shape of gasdispersion channel 134. Therefore, in some embodiments, the processchamber 100 further includes a gas distribution plate 125 having aplurality of apertures 126 disposed through the gas distribution plate125. The gas distribution plate 125 extends to the surface of the gasdispersion channel 134 such that the only pathway from the gasdispersion channel 134 to the substrate is through the plurality ofapertures 126 of the gas distribution plate 125. The gas distributionplate 125 advantageously creates a choked flow of gas through the gasdistribution plate 125 resulting in a more uniform deposition on thesubstrate 110 and, thus, substantially eliminating the donut-shapeddeposition caused by the rotational flow of gas.

In some embodiments, the gas distribution plate 125 is formed of anon-corrosive ceramic material such as, for example, aluminum oxide oraluminum nitride. In some embodiments, each of the plurality ofapertures 126 may have an equivalent fluid conductance. In someembodiments, a density of the plurality of apertures 126 (e.g., thenumber of apertures or the size of the openings of the apertures perunit area) may vary across the gas distribution plate 125 to achieve adesired deposition profile on the substrate 110. For example, a higherdensity of apertures 126 may be disposed at a center of the gasdistribution plate 125 to increase the deposition rate at the center ofthe substrate relative to the edge of the substrate to further improvedeposition uniformity.

Although the plurality of apertures 126 are depicted as cylindricalthrough holes, the plurality of apertures 126 may have differentprofiles. FIGS. 4A-C depict different non-limiting embodiments ofprofiles of the plurality of apertures 126. In the embodiment depictedin FIG. 4A, the aperture 126 is a cylindrical through hole having curvededges 402 that surround the aperture. In the embodiment depicted in FIG.4B, the aperture 126 is a through hole having an upper portion 404 thattapers inwardly toward a center of the aperture, a cylindrical centerportion 405 extending perpendicularly to an upper surface 127 of the gasdistribution plate 125, and a lower portion 406 that tapers outwardlyfrom the center of the aperture. In the embodiment depicted in FIG. 4C,the aperture 126 is a through hole having an upper portion 408 having acountersunk hole, a cylindrical center portion 409 extendingperpendicularly to the upper surface 127 of the gas distribution plate125, and a lower portion 410 that tapers outwardly from the center ofthe aperture. Other profiles of the plurality of apertures 126 mayalternatively be used to achieve optimal deposition uniformity duringprocessing of the substrate 110.

Not wishing to be bound by theory, the inventors believe that thediameter of gas dispersion channel 134, which is constant from the upperportion of gas dispersion channel 134 to a first point along centralaxis 133 and increasing from the first point to lower portion 135 of gasdispersion channel 134, allows less of an adiabatic expansion of a gasthrough gas dispersion channel 134 which helps to control thetemperature of the process gas contained in the circular gas flow 174.For example, a sudden adiabatic expansion of a gas delivered into gasdispersion channel 134 may result in a drop in the temperature of thegas which may cause condensation of the gas and formation of droplets.On the other hand, a gas dispersion channel 134 that gradually tapers isbelieved to provide less of an adiabatic expansion of a gas. Therefore,more heat may be transferred to or from the gas, and, thus, thetemperature of the gas may be more easily controlled by controlling thetemperature of chamber lid assembly 132. Gas dispersion channel 134 maygradually taper and contain one or more tapered inner surfaces, such asa tapered straight surface, a concave surface, a convex surface, orcombinations thereof or may contain sections of one or more taperedinner surfaces (i.e., a portion tapered and a portion non-tapered).

As shown in FIG. 3, the upper portion of the gas dispersion channel 134is defined by an insert 300 disposed in an inner region of a housing375. The insert 300 includes a cap 302 at an upper portion of the insert300 and a central passageway that at least partially defines the gasdispersion channel 134. The cap 302 extends over the housing 375 to holdthe insert 300 in place. The insert 300 and cap 302 include a pluralityof o-rings 385 disposed between the insert 300 and the housing 375 toensure proper sealing. The insert 300 includes a plurality ofcircumferential apertures which, when the insert 300 is inserted intothe housing 375, form a corresponding plurality of circumferentialchannels 360, 365, 370. The plurality of circumferential channels 360,365, 370 are fluidly coupled to the gas dispersion channel 134 via acorresponding plurality of holes 340, 345, 350. In the embodiment shownin FIG. 3, the gas delivery system 130 is coupled to the gas dispersionchannel 134 via a plurality of gas feed lines 310, 315, 320. The gasfeed lines 310, 315, 320 are fluidly coupled to the plurality ofcircumferential channels 360, 365, 370 to provide one or more gases tothe gas dispersion channel 134.

Returning to FIGS. 1 and 2, the process chamber 100 further includes achamber cleaning system including a remote plasma source (RPS) 190, anisolation collar 192 coupled to the RPS 190 at one end and the cap 302at an opposite end, a heater plate 198 coupled to an upper surface ofthe lid plate 170, and a cleaning gas (i.e., purge gas) source 197fluidly coupled to the RPS 190. The cleaning gas source may include anygas suitable for forming a plasma to clean the process chamber 100. Insome embodiments, for example, the cleaning gas may be nitrogentrifluoride (NF.sub.3). The isolation collar 192 includes an innerchannel 193 that is fluidly coupled to the gas dispersion channel 134through a plurality of holes 285 disposed in a central portion of thecap 302 to flow a plasma from the RPS 190 through the gas dispersionchannel 134 and into the reaction zone 164. The heater plate 198 may beformed of stainless steel and include a plurality of resistive heatingelements dispersed throughout the plate.

Typically, a cleaning gas is flowed through the gas dispersion channel134 and the reaction zone 164 after a first gas is provided to the gasdispersion channel 134 by the gas delivery system 130 to quickly purgethe first gas from the gas dispersion channel 134 and the reaction zone164. Subsequently, a second gas is provided by the gas delivery system130 to the gas dispersion channel 134 and the cleaning gas is againflowed through the gas dispersion channel 134 to the reaction zone 164to quickly purge the second gas from the gas dispersion channel 134 andthe reaction zone 164. However, the addition of the gas distributionplate 125 chokes the flow of the cleaning gas to the pumping channel 179and prolongs the cleaning process. As such, the inventors haveincorporated an exhaust system 180 having an exhaust conduit 184 coupledto the isolation collar 192 at a first end 186 and to the pumpingchannel 179 at a second end 188. A valve 182 is disposed in the exhaustconduit 184 to selectively fluidly couple the exhaust conduit 184 to theinner channel 193. In some embodiments, for example, the valve 182 maybe a plunger type valve having a plunger 202 that is moveable between afirst position (shown in FIG. 2) to fluidly couple the exhaust conduit184 to the inner channel 193 and a second position to seal off theexhaust conduit 184 from the inner channel 193. Each time the cleaninggas is flowed through the gas dispersion channel 134 and the reactionzone 164, the valve 182 is opened and the cleaning gas is rapidlyexhausted to the pumping channel 179.

When a pressure inside of the process chamber 100 exceeds a pressureinside of the RPS 190, processing gasses may flow up to and damage theRPS 190. The plurality of holes 285 serve as a choke point to prevent abackflow of processing gases from flowing up through the inner channel193 and into the RPS 190. The isolation collar 192 may be formed of anymaterial that is non-reactive with the cleaning gas being used. In someembodiments, the isolation collar 192 may be formed of aluminum when thecleaning gas is NF.sub.3. In some embodiments, the isolation collar 192and the insert 300 may be formed of aluminum and coated with a coatingto prevent corrosion of the isolation collar 192 and the insert 300 fromcorrosive gases when used. For example, the coating may be formed ofnickel or aluminum oxide.

Referring to FIG. 3, the RPS 190 operates at a temperature less than orequal to about 40° C. In order advantageously insulate the RPS 190 fromheat generated in the process chamber 100, a thermal isolation ring 394is disposed between the isolation collar 192 and the cap 302. Thethermal isolation ring 394 is formed of a metal with low thermalconductivity (e.g., lower than the thermal conductivity of the isolationcollar 192 and the cap 302). In addition, an o-ring 385 may also bedisposed between the isolation collar 192 and the cap 302 to furtherreduce the contact area between the isolation collar 192 and the cap302. The combination of the thermal isolation ring 394 and the o-ring385 acts as a thermal choke to ensure that the heat generated in theprocess chamber 100 does not adversely affect the RPS 190.

In some embodiments, when the lid plate 170 is heated above 100° C. theprocess chamber 100 may include a differential pumping line 250 toensure that any process gases or byproducts trapped between o-rings 385are exhausted to the pumping channel 179. The differential pumping line250 is coupled to the lid plate 170 at a first end and to the housing375 at a second end opposite the first end. The differential pumpingline is fluidly coupled to the gas dispersion channel 134 and to one ormore channels 260 formed at areas between two or more o-rings 385. Whenthe valve 182 is opened to exhaust the gas dispersion channel 134, thedifferential pumping line exhausts gases trapped between o-rings 385.

Returning to FIG. 3, a portion of bottom surface 160 of chamber lidassembly 132 may be contoured or angled downwardly and outwardly from acentral opening coupled to the gas dispersion channel 134 to aperipheral portion of chamber lid assembly 132 to help provide animproved velocity profile of a gas flow from gas dispersion channel 134across the surface of substrate 110 (i.e., from the center of thesubstrate to the edge of the substrate). Bottom surface 160 may containone or more surfaces, such as a straight surface, a concave surface, aconvex surface, or combinations thereof. In one embodiment, bottomsurface 160 is convexly funnel-shaped.

In one example, bottom surface 160 is downwardly and outwardly slopingtoward an edge of the substrate receiving surface 111 to help reduce thevariation in the velocity of the process gases traveling between bottomsurface 160 of chamber lid assembly 132 and substrate 110 whileassisting to provide uniform exposure of the surface of substrate 110 toa reactant gas. The components and parts of chamber lid assembly 132 maycontain materials such as stainless steel, aluminum, nickel-platedaluminum, nickel, alloys thereof, or other suitable materials. In oneembodiment, lid plate 170 may be independently fabricated, machined,forged, or otherwise made from a metal, such as aluminum, an aluminumalloy, steel, stainless steel, alloys thereof, or combinations thereof.

In some embodiments, inner surface 131 of gas dispersion channel 134 andbottom surface 160 of chamber lid assembly 132 may contain a mirrorpolished surface to help a flow of a gas along gas dispersion channel134 and bottom surface 160 of chamber lid assembly 132.

Referring to FIGS. 1-3, in a processing operation, substrate 110 isdelivered to process chamber 100 through slit valve 108 by a robot (notshown). Substrate 110 is positioned on substrate support 112 throughcooperation of lift pins 120 and the robot. Substrate support 112 raisessubstrate 110 into close opposition to a lower surface of the gasdistribution plate 125. A first gas flow may be injected into gasdispersion channel 134 of process chamber 100 by the gas delivery system130 together or separately (i.e., pulses) with a second gas flow. Thefirst gas flow may contain a continuous flow of a purge gas from a purgegas source and pulses of a reactant gas from a reactant gas source ormay contain pulses of a reactant gas from the reactant gas source andpulses of a purge gas from the purge gas source. The second gas flow maycontain a continuous flow of a purge gas from a purge gas source andpulses of a reactant gas from a reactant gas source or may containpulses of a reactant gas from a reactant gas source and pulses of apurge gas from a purge gas source.

The circular gas flow 174 travels through gas dispersion channel 134 andsubsequently through the plurality of apertures 126 in the gasdistribution plate 125. The gas is then deposited on the surface ofsubstrate 110. Bottom surface 160 of chamber lid assembly 132, which isdownwardly sloping, helps reduce the variation of the velocity of thegas flow across the surface of gas distribution plate 125. Excess gas,byproducts, etc. flow into the pumping channel 179 and are thenexhausted from process chamber 100. Throughout the processing operation,the heater plate 198 may heat the chamber lid assembly 132 to apredetermined temperature to heat any solid byproducts that haveaccumulated on walls of the process chamber 100 (or a processing kitdisposed in the chamber). As a result, any accumulated solid byproductsare vaporized. The vaporized byproducts are evacuated by a vacuum system(not shown) and pumping channel 179. In some embodiments, thepredetermined temperature is greater than or equal to 150° C.

Some process conditions can cause step coverage issues due to, forexample, residual precursors in the gas delivery system allowing gasphase reactions. In a typical ALD process, gas phase reactions aregenerally avoided. Accordingly, some embodiments of the disclosureprovide process chamber lids and processing chambers with backsidepumping capability to a chamber lid. The apparatus of some embodimentsis a thermal chamber lid with no plasma source connected thereto. Insome embodiments, the chamber lid is configured with a remote plasmasource to provide a remote plasma to the process chamber.

One or more embodiments of the disclosure advantageously provideapparatus to improve step coverage of films on surface features. One ormore embodiments of the disclosure advantageously provide apparatus thatadds backside pumping to remove residual reactive gases. In someembodiments, the apparatus helps pump chemicals trapped between the lidplate and the showerhead more efficiently.

FIG. 5 shows a process chamber lid assembly 500 according to one or moreembodiment of the disclosure. A housing 375 encloses a gas dispersionchannel 134 that extends along a central axis 133 of the housing 375.The gas dispersion channel 134 has an upper portion 134 a and a lowerportion 134 b.

A lid plate 170 is coupled to the housing 375 and has a contoured bottomsurface 160. The contoured bottom surface 160 extends downwardly andoutwardly from a central opening 136 coupled to the lower portion 134 bof the gas dispersion channel 134 to an outer peripheral portion 138 ofthe lid plate 170. In the illustrated embodiment, the outer peripheralportion 138 refers to the outer portion of the contoured bottom surface160 adjacent the outer peripheral edge 137.

The lid assembly 500 includes a gas distribution plate 125 disposedbelow the lid plate 170. The gas distribution plate 125 has a topsurface 128 and a bottom surface 129 with a plurality of apertures 126disposed through the gas distribution plate 125 from the top surface 128to the bottom surface 129.

The gas distribution plate 125 has an upper outer peripheral contour 520configured to form a pumping channel 530 between the gas distributionplate 125 and the lid plate 170. The pumping channel 530 shown in theembodiment of FIG. 5 is defined between an outer peripheral bottomsurface 532 of the lid plate 170 and the upper outer peripheral contour520 of the gas distribution plate 125. In some embodiments, the outerperipheral bottom surface 532 of the lid plate 170 is further from thecentral axis 133 than the outer peripheral portion 138 of the contouredbottom surface 160. Stated differently, in some embodiments, the outerperipheral bottom surface 532 surrounds the contoured bottom surface160.

The contoured bottom surface 160 of the lid plate 170 and the topsurface 128 of the gas distribution plate 125 define a gap G. As thebottom surface 160 is contoured, the gap G is variable as a function ofdistance from the central axis 133. In some embodiments, the inner zoneZ_(I) has a larger gap than the middle zone Z_(M), and the middle zoneZ_(M) has a larger gap than the outer zone Z_(O). FIG. 6A shows aschematic cross-sectional view of the lid plate 170 with a contouredbottom surface 160 similar to that shown in FIG. 5. FIG. 6B shows aschematic cross-sectional view of the lid plate 170 and gas distributionplate 125 of FIG. 5 showing the relationship of the gap G to the radialdistance from the central axis 133. In FIG. 6A, the contoured bottomsurface 160 of the lid plate 170 is separated into three zones: an innerzone Z_(I); a middle zone Z_(M); and an outer zone Z_(O). In thisembodiment, in the middle zone Z_(M) the contoured bottom surface 160 isflat so that the gap G_(M) is uniform. Referring to FIG. 6B, which showsa partial cross-sectional view, the gap G_(M) in the middle zone Z_(M)is uniform from the left edge to the right edge of the middle zoneZ_(M). In the inner zone Z_(I), the gap G_(I) is a function of thedistance x measured from the central axis 133. FIG. 6B shows twomeasurements for the gap G_(I)dx in the inner zone Z_(I). In the outerzone Z_(O), the gap G_(O) is a function of the distance x measured fromthe central axis 133. One measurement is shown in FIG. 6B for the gapG_(O)dx in the outer zone Z_(O). The skilled artisan will recognize thatthe illustrated measurements are for descriptive purposes only. Theapertures 126 in the gas distribution plate 125 in FIG. 6B are omittedfor descriptive purposes.

Referring again to FIG. 6B, in some embodiments, the inner zone Z_(I) isdefined from a central axis 133 of the lid plate 170 to an inner zoneradial distance RI from the central axis 133. The middle zone Z_(M) isdefined from the inner zone radial distance R_(I) to a middle zoneradial distance R_(M) from the central axis 133. The outer zone Z_(O) ismeasured from the middle zone radial distance Z_(M) to an outer zoneradial distance R_(O) at an outer peripheral edge 137 of the contouredbottom surface 160.

The size of the middle zone Z_(M) can be any suitable size measuredrelative to the total radial distance from the central axis 133 to theouter peripheral edge 137. In some embodiments, the distance from thecentral axis 133 to the outer peripheral edge 137 is greater than orequal to about 50 mm, 100 mm, 150 mm or 200 mm. In some embodiments, thedistance from the central axis 133 to the outer peripheral edge 137 isgreater than the radius of a substrate to be processed. For example, inan embodiment where a 300 mm substrate is being processed, the radialdistance from the central axis to the edge of the substrate is, assumingthe substrate is centered, 150 mm. In this example, the distance fromthe central axis 133 to the outer peripheral edge 137 is greater than orequal to 150 mm.

In some embodiments, the distance from the central axis 133 to themiddle zone radial distance Z_(M) is greater than or equal to about 50mm, 100 mm, 150 mm or 200 mm. In some embodiments, the distance from thecentral axis 133 to the middle zone radial distance Z_(M) is greaterthan the radius of a substrate to be processed. For example, in anembodiment where a 300 mm substrate is being processed, the radialdistance from the central axis to the edge of the substrate is, assumingthe substrate is centered, 150 mm. In this example, the distance fromthe central axis 133 to the middle zone radial distance Z_(M) is greaterthan or equal to 150 mm, for example.

In some embodiments, the size of the middle zone Z_(M) of the lid plate170 is in the range of about 10% to about 90% of the distance from thecentral axis to the outer zone radial distance R_(O). In someembodiments, the size of the middle zone Z_(M) of the lid plate 170 isin the range of about 20% to about 80%, or in the range of about 30% toabout 70%, or in the range of about 40% to about 60% of the distancefrom the central axis 133 to the outer zone radial distance R_(O).

In some embodiments, substantially uniform gap in the middle zone Z_(M)is in the range of about 0.1 inches to about 2 inches (about 2.5 mm toabout 51 mm). As used in this manner, the term “substantially uniformgap” means that the gap at any radial distance within the middle zoneZ_(M) is within 5%, 2%, 1% or 0.5% of the average gap in the middle zoneZ_(M).

In some embodiments, the outer zone Z_(O) is sloped from the middle zoneZ_(M) to a front face 161 of the lid plate 170. In some embodiments, theouter zone Z_(O) is sloped form the middle zone Z_(M) to the top surface128 of the gas distribution plate 125. The slope of the outer zone Z_(O)in relation to the flat middle zone Z_(M) forms an outer zone angle Θ,as shown in FIG. 7. In some embodiments, the outer zone angle is in therange of about 15° to about 75°, or in the range of about 30° to about60°, or in the range of about 40° to about 50°.

Referring to FIGS. 5 and 7, in some embodiments, the outer zone Z_(O) ofthe contoured bottom surface 160 is connected to the pumping channel 530through pumping holes 525 formed in the lid plate 170. In someembodiments, the pumping holes 525 are formed in the outer zone Z_(O) ofthe contoured bottom surface 160. The number of pumping holes 525 can bevaried based on, for example, the size of the lid plate 170. In someembodiments, there are in the range of about 24 to about 144 pumpingholes 525.

As shown in FIG. 7, the pumping holes intersect the outer zone Z_(O) ofthe contoured bottom surface 160 at an angle ϕ. In some embodiments, theangle ϕ is in the range of about 75° to about 105°, or in the range ofabout 80° to about 100°, or in the range of about 85° to about 95°, orin the range of about 88° to about 92°.

The lid assembly 500 of some embodiments includes at least one pump port560 in fluid communication with the pumping channel 530, as shown inFIG. 5. The pump port 560 can be a separate component connected to thelid plate 170. In some embodiments, there are two or more pump ports 560connected to the pumping channel 530 at different radial positions. Insome embodiments, each of the pump ports is connected to a separatevacuum source for evacuation purposes. In some embodiments, the pumpports are in fluid communication with a single vacuum source. In someembodiments, the pump ports are in fluid communication with the pumpingchannel 179 (see FIG. 1).

FIG. 8 shows a lid assembly 600 in accordance with one or moreembodiment of the disclosure. The contoured bottom surface 160 of thelid plate 170 is sloped from an inner edge 610 of the contoured bottomsurface 160 to the outer peripheral edge 137.

The slope of the contoured bottom surface 160 creates a gap G thatdecreases to a minimum at the outer peripheral edge 137. In someembodiments, the minimum gap G is in the range of about 0.01 inches toabout 1 inches (about 0.25 mm to about 25.4 mm), or in the range ofabout 0.05 inches to about 0.5 inches (about 1.25 mm to about 12.7 mm).

Additional embodiments of the disclosure are directed to processingchambers incorporating lid assembly 500 or lid assembly 600.

In the foregoing specification, embodiments of the disclosure have beendescribed with reference to specific exemplary embodiments thereof. Itwill be evident that various modifications may be made thereto withoutdeparting from the broader spirit and scope of the embodiments of thedisclosure as set forth in the following claims. The specification anddrawings are, accordingly, to be regarded in an illustrative senserather than a restrictive sense.

What is claimed is:
 1. A process chamber lid assembly, comprising: ahousing enclosing a gas dispersion channel that extends along a centralaxis of the housing, the gas dispersion channel having an upper portionand a lower portion; a lid plate coupled to the housing and having acontoured bottom surface that extends downwardly and outwardly from acentral opening coupled to the lower portion of the gas dispersionchannel to a peripheral portion of the lid plate, the contoured bottomsurface of the lid plate comprises an inner zone, a middle zone and anouter zone, the inner zone defined from a central axis of the lid plateto an inner zone radial distance from the central axis, the middle zonedefined from the inner zone radial distance to a middle zone radialdistance from the central axis, and the outer zone measured from themiddle zone radial distance to an outer zone radial distance at an outerperipheral edge of the contoured bottom surface; and a gas distributionplate disposed below the lid plate, the gas distribution plate having anupper outer peripheral contour configured to form a pumping channelbetween the gas distribution plate and the lid plate, the gasdistribution plate having a top surface and a bottom surface with aplurality of apertures disposed through the gas distribution plate fromthe top surface to the bottom surface, the contoured bottom surface ofthe lid plate and top surface of the gas distribution plate defining agap, the inner zone of the contoured bottom surface of lid having alarger gap than the middle zone of the contoured bottom surface of thelid, the middle zone of the contoured bottom surface of the lid having alarger gap than the outer zone of the contoured bottom surface of thelid, the outer zone is sloped from the middle zone to a front face ofthe lid plate forming an outer zone angle, the outer zone of thecontoured bottom surface is connected to the pumping channel throughpumping holes formed in the lid plate.
 2. The lid assembly of claim 1,wherein the middle zone of the contoured bottom surface forms asubstantially uniform gap.
 3. The lid assembly of claim 2, wherein thesubstantially uniform gap is in the range of about 0.1 inch to about 2inches.
 4. The lid assembly of claim 1, wherein the middle zonecomprises in the range of about 10% to about 90% of the distance fromthe central axis to the outer zone radial distance.
 5. The lid assemblyof claim 1, wherein the pumping holes are formed in the outer zone ofthe contoured bottom surface.
 6. The lid assembly of claim 1, whereinthe pumping holes intersect the outer zone of the contoured bottomsurface at an angle in the range of about 85° to about 95°.
 7. The lidassembly of claim 1, wherein there are in the range of about 24 to about144 pumping holes in the outer zone.
 8. The lid assembly of claim 1,further comprising at least one pump port in fluid communication withthe pumping channel.
 9. A processing chamber comprising the lid assemblyof claim
 1. 10. The processing chamber of claim 9, further comprising aremote plasma source fluidly coupled to the gas dispersion channel.